EBC Day 11 – Everest Base Camp

That morning, a sad farewell took place in Lobouche (elevation : 4940m) amongst a group of hikers from New Zealand. One of the party members apparently had been suffering from a bad headache and had just begun mumbling unintelligibly. It was (wisely) decided that he would need to make a quick descent back down to lower altitudes, whilst the rest of the party continued up to Gorak Chep (elevation : 5164m). I say wise because the altered mental status (a.k.a AMS) indicated an onset of HACE.
As one ascends to higher altitudes, the saturation of the atmospheric gases decreases, which results in mild hypoxia--a deficiency in the amount of oxygen that reaches the body tissues. One's breathing and heart rate are then forced to increase in order to combat this hypoxia. The capillaries in the body also dilate, and the capillary leakage causes swelling (edema). Without sufficient acclimatisation, the signs and symptoms that one might encounter are:

If you encounter any of those signs and symptoms, it is important to stop your ascent and rest, and consider a descent of 500m or more. Treat the symptoms with analgesics and antiemetics as necessary, and consider the administration of acetazolamide (125 to 250 mg twice daily), otherwise known as 'Diamox'. Acute mountain sickness can progress to 'High-Altitude Pulmonary Edema' (HAPE) or 'High-Altitude Cerebral Edema' (HACE), both of which are potentially fatal.

Testing out the Gamow bag at the TOPCOM conference. The Gamow bag allows medical practitioners to increase the air pressure that surrounds the patient in order to simulate a descent from altitude, which is the definitive treatment of altitude illness (AMS, HACE and HAPE).

Hape & Hace

High-Altitude Pulmonary Edema (HAPE) occurs when fluid leaks from the capillary beds in the lungs and into the alveoli, and causes swelling of lung tissue. HAPE tends to develop several days after arrival at moderate altitudes of (3000m to 4000m).

It is important to minimise exertion and to keep the patient warm before making an immediate descent. Initial administration of oxygen should be at a rate of 4-6 l/min until conditions improve, after which the rate is then lowered to 2-4 l/min. Moderate HAPE can quickly deteriorate into severe HAPE in a matter of hours, which will ultimately result in respiratory failure and eventual death. Pulmonary edema can sometimes persist for days after a descent has been made and quite often requires hospital observation and treatment.
High-Altitude Cerebral Edema (HACE) on the other hand, occurs when fluid leaks into the brain. This presents as brain swelling and an increase in intracranial pressure (ICP).

ABOUT THE AUTHOR

"Ramon is a hiker, climber, and diver who loves to get off the beaten path. His website is a combination of his drive to explore and his passion to capture and share what he sees. Ramon is a bit of a minimalist and is currently torn between his yearning to travel the world and his need to decrease his carbon footprint. Read more here." View all posts by Ramon Fadli